Gas turbines, which may also be referred to as combustion turbines, are internal combustion engines that accelerate gases, forcing the gases into a combustion chamber where heat is added to increase the volume of the gases. The expanded gases are then directed towards a turbine to extract the energy generated by the expanded gases. Gas turbines have many practical applications, including usage as jet engines and in industrial power generation systems.
The acceleration and directing of gases within a gas turbine are often accomplished using rotating blades. Extraction of energy is typically accomplished by forcing expanded gases from the combustion chamber towards gas turbine blades that are spun by the force of the expanded gases exiting the gas turbine through the turbine blades. Due to the high temperatures of the exiting gases, gas turbine blades must be constructed to endure extreme operating conditions. In many systems, complex turbine blade cooling systems are employed. While gas turbine blades are commonly constructed from metals, more advanced materials are now being used for such blades, such as ceramics and ceramic matrix composites. When using such advanced materials or simply metal in constructing gas turbine blades, coatings may be applied to provide added protection to the blades and increased heat resistance.